Single yellow or brown sugar leaf on an otherwise green cola
Sudden; the leaf pulls out easily and the bud tissue around it is brown and mushy inside..
- Also called
- one dead leaf in bud
- brown leaf in my bud
- bud rot sign
- dead sugar leaf pulls out easily
Likely causes, most likely first
Ranked for this sign on its own. Your stage, medium and readings change the order, so run the checker for your plant.
LikelyBotrytis bud rot (grey mould)
Fix: Act now. Bag infected buds before cutting them out, 3-5 cm (1-2 in) past visible rot, and clean tools; never shake them. Drop RH to about 40-50% in late flower, control the lights-off dew point, move air through dense colas. There is no cure in flower; consider harvesting early if it keeps spreading.
Recovery: No new rot on weekly cola checks for 2 weeks.
How to confirm it
- Open the densest colas. In flower, gently spread the largest, densest colas at the base and look for brown, mushy or grey tissue around the stem, a single wilted sugar leaf that pulls out easily, frass or caterpillars. Check 5-10 colas per plant each week from mid-flower, more when RH is high. Bag any rot before removing it.
- Check temperature and RH at canopy height with a calibrated sensor. Put a calibrated sensor (salt test: a sealed bag with damp table salt reads 75% RH after 8-12 hours) at canopy height, out of direct light, and log for 24 hours including lights-off. Look for lights-off RH spikes and dew point.
Look for
A lone wilted, yellow-brown sugar leaf sticking out of a dense cola; then the bud gently opened..
The full guide: Botrytis (bud rot / grey mould) in cannabis
Guidance, not a guarantee. The checker weighs common causes against what you tell it; confirm with the tests before you treat, change one thing at a time and watch the new growth.
